Dietary and lifestyle factors in relation to plasma insulin-like growth factor I in a general population sample

Associations between food group intakes and circulating insulin-like growth factor-I in the UK Biobank: a cross-sectional analysis

PURPOSE

Circulating insulin-like growth factor-I (IGF-I) concentrations have been positively associated with risk of several common cancers and inversely associated with risk of bone fractures. Intakes of some foods have been associated with increased circulating IGF-I concentrations; however, evidence remains inconclusive. Our aim was to assess cross-sectional associations of food group intakes with circulating IGF-I concentrations in the UK Biobank.

METHODS

At recruitment, the UK Biobank participants reported their intake of commonly consumed foods. From these questions, intakes of total vegetables, fresh fruit, red meat, processed meat, poultry, oily fish, non-oily fish, and cheese were estimated. Serum IGF-I concentrations were measured in blood samples collected at recruitment. After exclusions, a total of 438,453 participants were included in this study. Multivariable linear regression was used to assess the associations of food group intakes with circulating IGF-I concentrations.

RESULTS

Compared to never consumers, participants who reported consuming oily fish or non-oily fish ≥ 2 times/week had 1.25 nmol/L (95% confidence interval:1.19-1.31) and 1.16 nmol/L (1.08-1.24) higher IGF-I concentrations, respectively. Participants who reported consuming poultry ≥ 2 times/week had 0.87 nmol/L (0.80-0.94) higher IGF-I concentrations than those who reported never consuming poultry. There were no strong associations between other food groups and IGF-I concentrations.

CONCLUSIONS

We found positive associations between oily and non-oily fish intake and circulating IGF-I concentrations. A weaker positive association of IGF-I with poultry intake was also observed. Further research is needed to understand the mechanisms which might explain these associations.

Associations of circulating insulin-like growth factor-I with intake of dietary proteins and other macronutrients

BACKGROUND & AIMS

Circulating insulin-like growth factor-I (IGF-I) is associated with the risk of several cancers. Dietary protein intake, particularly dairy protein, may increase circulating IGF-I; however, associations with different protein sources, other macronutrients, and fibre are inconclusive. To investigate the associations between intake of protein, macronutrients and their sources, fibre, and alcohol with serum IGF-I concentrations.

METHODS

A total of 11,815 participants from UK Biobank who completed ≥4 24-h dietary assessments and had serum IGF-I concentrations measured at baseline were included. Multivariable linear regression was used to assess the cross-sectional associations of macronutrient and fibre intake with circulating IGF-I concentrations.

RESULTS

Circulating IGF-I concentrations were positively associated with intake of total protein (per 2.5% higher energy intake: 0.56 nmol/L (95% confidence interval: 0.47, 0.66)), milk protein: 1.20 nmol/L (0.90, 1.51), and yogurt protein: 1.33 nmol/L (0.79, 1.86), but not with cheese protein: -0.07 nmol/L (-0.40, 0.25). IGF-I concentrations were also positively associated with intake of fibre (per 5 g/day higher intake: 0.46 nmol/L (0.35, 0.57)) and starch from wholegrains (Q5 vs. Q1: 1.08 nmol/L (0.77, 1.39)), and inversely associated with alcohol consumption (>40 g/day vs <1 g/day: -1.36 nmol/L (-1.00, -1.71)).

CONCLUSIONS

These results show differing associations with IGF-I concentrations depending on the source of dairy protein, with positive associations with milk and yogurt protein intake but no association with cheese protein. The positive association of fibre and starch from wholegrains with IGF-I warrants further investigation.

PM2.5-bound PAHs exposure linked with low plasma insulin-like growth factor 1 levels and reduced child height

BACKGROUND

Exposure to atmospheric fine particle matter (PM_2.5) pollution and the absorbed pollutants is known to contribute to numerous adverse health effects in children including to growth.

OBJECTIVE

The aim of this study was to evaluate exposure levels of atmospheric PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) in an electronic waste (e-waste) polluted town, Guiyu, and to investigate the associations between PM_2.5-PAH exposure, insulin-like growth factor 1 (IGF-1) levels and child growth.

METHODS

This study recruited 238 preschool children (3-6 years of age), from November to December 2017, of which 125 were from Guiyu (an e-waste area) and 113 were from Haojiang (a reference area). Levels of daily PM_2.5 and PM_2.5-bound ∑16 PAHs were assessed to calculate individual chronic daily intakes (CDIs). IGF-1 and IGF-binding protein 3 (IGFBP-3) concentrations in child plasma were also measured. The associations and further mediation effects between exposure to PM_2.5 and PM_2.5-bound PAHs, child plasma IGF-1 concentration, and child height were explored by multiple linear regression models and mediation effect analysis.

RESULTS

Elevated atmospheric PM_2.5-bound ∑16 PAHs and PM_2.5 levels were observed in Guiyu, and this led to more individual CDIs of the exposed children than the reference (all P < 0.001). The median level of plasma IGF-1 in the exposed group was lower than in the reference group (91.42 ng/mL vs. 103.59 ng/mL, P < 0.01). IGF-1 levels were negatively correlated with CDIs of PM_2.5, but not with CDIs of PM_2.5-bound ∑16 PAHs after adjustment. An increase of 1 μg/kg of PM_2.5 intake per day was associated with a 0.012 cm reduction of child height (95% CI: -0.014, -0.009), and similarly, an elevation of 1 ng/kg of PM_2.5-bound ∑16 PAHs intake per day was associated with a 0.022 cm decrease of child height (95% CI: -0.029, -0.015), both after adjustment of several potential confounders (age, gender, family cooking oil, picky eater, eating sweet food, eating fruits or vegetables, parental education level and monthly household income). The decreased plasma IGF-1 concentration mediated 15.8% of the whole effect associated with PM_2.5 exposure and 23.9% of the whole effect associated with PM_2.5-bound ∑16 PAHs exposure on child height.

CONCLUSION

Exposure to atmospheric PM_2.5-bound ∑16 PAHs and PM_2.5 is negatively associated with child height, and is linked to reduced IGF-1 levels in plasma. This may suggest a causative negative role of atmospheric PM_2.5-bound exposures in child growth.

Perfluoroalkyl Substances, Sex Hormones, and Insulin-like Growth Factor-1 at 6-9 Years of Age: A Cross-Sectional Analysis within the C8 Health Project

BACKGROUND

Exposure to some perfluoroalkyl substances (PFAS), such as perfluorohexane sulfonate (PFHxS), perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA), may alter levels of sex hormones and insulin-like growth factor-1 (IGF-1) in animals. Human studies on this topic are scarce, and none have been conducted in young children.

OBJECTIVES

We investigated the relationship between levels of PFAS and estradiol, total testosterone, and IGF-1 in 2,292 children (6-9 years of age) from the C8 Health Project who lived near a chemical plant in the Mid-Ohio Valley (USA) with local contamination from PFOA.

METHODS

Serum samples were collected in 2005-2006 and analyzed for PFAS, sex hormones, and IGF-1. Results from regression models were expressed as the adjusted percentage difference (95% CI) per sex-specific interquartile range (IQR) increment of each PFAS serum concentration. Analyses by PFAS quartiles were also conducted.

RESULTS

Median concentrations of PFHxS, PFOA, PFOS, and PFNA were 8, 35, 22, and 1.7 ng/mL in boys and 7, 30, 21, and 1.7 ng/mL in girls. In boys, PFOA concentrations were significantly associated with testosterone levels (-4.9%; 95% CI: -8.7, -0.8%); PFOS with estradiol (-4.0%; 95% CI: -7.7, -0.1%), testosterone (-5.8%; 95% CI: -9.4, -2.0%), and IGF-1 (-5.9%; 95% CI: -8.3, -3.3%); and PFNA with IGF-1 (-3.5%; 95% CI: -6.0, -1.0%). In girls, significant associations were found between PFOS and testosterone (-6.6%; 95% CI: -10.1, -2.8%) and IGF-1 (-5.6%; -8.2, -2.9%); and PFNA and IGF-1 (-3.8%; 95% CI: -6.4, -1.2%). In both sexes, the magnitudes of the associations decreased monotonically across quartiles for both testosterone and IGF-1 in relation to PFOS, and for IGF-1 and PFNA in girls.

CONCLUSIONS

To our knowledge, this is the first study suggesting that PFAS are associated with lower levels of IGF-1 and sex hormones in young children.

CITATION

Lopez-Espinosa MJ, Mondal D, Armstrong BG, Eskenazi B, Fletcher T. 2016. Perfluoroalkyl substances, sex hormones, and insulin-like growth factor-1 at 6-9 years of age: a cross-sectional analysis within the C8 Health Project. Environ Health Perspect 124:1269-1275; http://dx.doi.org/10.1289/ehp.1509869.

Effects of 2,4-dichlorophenoxyacetic acid on the ventral prostate of rats during the peri-pubertal, pubertal and adult stage

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is used on a wide variety of terrestrial and aquatic broadleaf weeds. 2,4-D has been shown to produce a wide range of adverse effects on animal and human health. The aim of the current study was to evaluate the effects of pre- and postnatal exposure to 2,4-D on rat ventral prostate (VP). Pregnant rats were exposed daily to oral doses of 70 mg/kg/day of 2,4-D from 16 days of gestation up to 23 days after delivery. Then, the treated groups (n = 8) were fed with a 2,4-D added diet until sacrificed by decapitation on postnatal day (PND) 45, 60, or 90. Morphometric studies were performed and androgen receptor (AR) protein levels in the VP were determined. AR, insulin-like growth factor-I (IGF-1) and insulin-like growth factor-I receptor (IGF-1R) mRNA expression in the VP along with testosterone (T), dihydroxytestosterone (DHT), growth hormone (GH) and IGF-1 serum levels were also determined to ascertain whether these parameters were differentially affected. Results of this study showed that 2,4-D exposure during gestation and until adulthood altered development of the prostate gland in male rats, delaying it at early ages while increasing its size in adults, indicate that 2,4-D could behave as endocrine disruptors (EDs).

The relationship between dioxin-like polychlorobiphenyls and IGF-I serum levels in healthy adults: evidence from a cross-sectional study

OBJECTIVE

Insulin-like growth factor I (IGF-I) and dioxin-like polychlorobiphenyls (DL-PCBs) have been associated with the pathogenesis of several diseases like cancer, diabetes and growth disorders. Because it has been suggested that organohalogenated contaminants could influence IGF-I levels in adults, the potential relationship between DL-PCBs and IGF-I serum levels was studied in 456 healthy adults from a representative sample of the general population of the Canary Islands (Spain).

DESIGN

Free circulating serum levels of IGF-I and IGFBP-3 were measured through an ELISA methodology, while the serum levels of the 12 DL-PCBs congeners (IUPAC numbers # 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, and 189) were measured by gas chromatography/mass spectrometry (GC-MS).

RESULTS

DL-PCBs 156 and 167, Total DL-PCBs body burden (∑PCBs: sum over the 12 measured DL-PCBs), and Total toxic burden (in terms of toxic equivalence to dioxins: ∑TEQs) showed a trend of inverse association with IGF-I serum levels in the whole studied population. After adjusting for potential confounders, including gender, body mass index (BMI), age, and IGF-binding protein-3 (IGFBP-3), younger (18-45 years) women with lower BMI (<27 kg/m(2)) and detectable levels of DL-PCB-156 showed significantly lower IGF-I levels than those in the same age and BMI subgroup with non-detectable levels of DL-PCB-156 (p<0.001). Similarly, ∑PCBs and ∑TEQs showed a tendency to an inverse association with IGF-I levels in the same group of women (p=0.017 and p=0.019 respectively).

CONCLUSIONS

These findings suggest that DL-PCBs could be involved in the regulation of the IGF-system in a way possibly influenced by gender, age and BMI. Although these results should be interpreted with caution, such circumstances could contribute to explain the development of diseases associated to the IGF system.

Insulin-like growth factor-I (IGF-I) serum concentrations in healthy children and adolescents: relationship to level of contamination by DDT-derivative pesticides

CONTEXT

Serum levels of Insulin-like growth factor I (IGF-I) play a critical role in children growth and in the pathogenesis of several diseases. In addition, recent studies suggest that DDT-derivative organochlorine pesticides (OC-DDTs) could influence IGF levels in human beings.

OBJECTIVE AND DESIGN

Because it has been suggested that IGF-I peak levels at puberty could determine IGF-I levels in adulthood, we developed a cross-sectional study of the potential association between serum levels of OC-DDTs and IGF system in 160 serum samples from young people (81 boys and 79 girls) living in the Canary Islands (Spain).

RESULTS

Multivariate tests were used adjusting for confounding variables (age, height, and weight) and stratifying by gender and age: IGF-I serum levels were significantly lower in pre-pubertal male children (6-15years) who showed detectable values of p,p'-DDE, and p,p'-DDD than in pre-pubertal male children with undetectable levels of these OC-DDTs-metabolites (p=0.023 and p=0.049, respectively). In addition, in this multivariate model, a non-linear dose-response curve was observed between Total DDT body burden (sum of the three DDT-derivatives measured: p,p'-DDT, p,p'-DDE, and p,p'-DDD) and IGF-I in pre-pubertal male children (6-15years; p=0.043).

CONCLUSION

These findings suggest that OC-DDTs could modulate the IGF-system in a way that is highly influenced by gender and age. Improvements in our understanding of exogenous determinants of the IGF-system may provide new insights into the role played by environmental contaminants in IGF-related diseases.

The association between diet and serum concentrations of IGF-I, IGFBP-1, IGFBP-2, and IGFBP-3 in the European Prospective Investigation into Cancer and Nutrition

Circulating concentrations of insulin-like growth factor I (IGF-I) and IGF binding proteins (IGFBP) have been associated with the risk of several types of cancer. Dietary correlates of IGF-I and IGFBPs are not yet well established. The objective of this study was to assess the association between dietary intake and serum concentrations of IGF-I, IGFBP-1, IGFBP-2, and IGFBP-3 in a cross-sectional analysis of 4,731 men and women taking part in the European Prospective Investigation into Cancer and Nutrition. Diet was assessed using country-specific validated dietary questionnaires. Serum concentrations of IGF-I, IGFBP-1, IGFBP-2 and IGFBP-3 were measured, and the associations between diet and IGF-I and IGFBPs were assessed using multiple linear regression adjusting for sex, age, body mass index, smoking status, and alcohol and energy intake. Each 1 SD increment increase in total and dairy protein and calcium intake was associated with an increase in IGF-I concentration of 2.5%, 2.4%, and 3.3%, respectively (P for trend <0.001 for all) and a decrease in IGFBP-2 of 3.5%, 3.5%, and 5.4% (P for trend <0.001 for all), respectively. There were no significant associations between the intake of protein or calcium from nondairy sources and IGF-I. The results from this large cross-sectional analysis show that either the intake of dairy protein or calcium is an important dietary determinant of IGF-I and IGFBP-2 concentrations; however, we suggest that it is more likely to be protein from dairy products.

Race/ethnic variation in serum levels of IGF-I and IGFBP-3 in US adults

OBJECTIVES

The IGF axis plays a significant role in normal growth and development and variation in IGFs is associated with health outcomes. Past studies report variation in IGF levels among race/ethnic groups known to differ in disease incidence. This paper reports on race/ethnic variation in serum levels of IGF-I and IGF-BP3 in a nationally representative and ethnically diverse sample of US adults.

DESIGN

Serum IGF-I and IGFBP-3 levels from the fasting subsample (n = 6061) of respondents to the US National Health and Nutrition Examination Survey III (NHANES III) were analyzed using an IGF-I ELISA (Diagnostic Systems Laboratory (DSL) 10-5600) and an IGFBP-3 IRMA (DSL 6600). The NHANES is a combined examination and interview survey of a nationally representative sample of US adults. Regression analyses were used to estimate cross-sectional associations between the IGF axis and demographic variables.

RESULTS

In unadjusted analyses, serum IGF-I levels were higher in males than in females, and IGFBP-3 levels were higher in females than in males. Both analytes were lower in older adults. Univariate analyses indicate that serum levels of IGF-I are lower in female Non-Hispanic Whites (NHW) (256 [4.9]) and Hispanics (249 [6.6]) than in Non-Hispanic Blacks (NHB) (281 [4.9]). However, in males, IGF levels in NHWs (287 [3.6]) and NHBs (284 [4.3]) are similar and levels in Mexican-Americans are only moderately reduced (265 [3.4]). Notably, NHB's have the highest molar ratio of IGF-I:IGFBP-3 at all ages. After adjustment for age and BMI, gender and race/ethnicity differences persist.

CONCLUSIONS

These cross-sectional data support exploration of the IGF axis as an explanation for some race/ethnic differences in cancer incidence.

Serum levels of insulin-like growth factor-I in relation to organochlorine pesticides exposure

CONTEXT

Insulin-like growth factor 1 (IGF-I) and organochlorine pesticides (OCs) have been involved in the pathogenesis of several diseases like cancer, diabetes and growth disorders.

OBJECTIVE AND DESIGN

The potential relationship between the serum levels of various OCs and serum IGF-I was investigated in adults (176 men and 247 women) from a representative sample of the general population of the Canary Islands (Spain).

RESULTS

After adjustment for potential confounders, which include body mass index, age, and IGF-binding protein-3 (IGFBP-3), IGF-I levels were significantly lower in the 247 women who showed detectable levels of p,p'-DDD (a DDT-metabolite) than in women who presented non-detectable levels of this pesticide (p=0.030), specially in 36-50 years old women. A similar negative relationship was also found between IGF-I and aldrin (a non-DDT-derivative) in women (p=0.049). In the group of 176 men, aldrin seemed to exert a similar negative effect on IGF-I (p=0.046) and this effect was clearly significant in the oldest group (51-65 years) (p=0.009). A non-linear dose-response curve was observed between Total Cyclodienes Body Burden (Total Cyclodienes; sum of aldrin, dieldrin and endrin) and IGF-I in men (p=0.024). These findings suggest that OCs could modulate the IGF-system in a way that is highly influenced by gender, age and by chemical or combination of chemicals implicated. Such circumstances may contribute to the development of a number of diseases related to IGF-I and should be taken into account in public health decisions.

Diet, serum insulin-like growth factor-I and IGF-binding protein-3 in European women

OBJECTIVE

The aim of this study was to examine the relationship of diet with serum insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 in women.

DESIGN

Cross-sectional study.

SETTING AND SUBJECTS

The population are 2109 women who were control subjects in a case-control study of breast cancer nested in the European Prospective Investigation into Cancer and Nutrition. Control subjects were randomly chosen among risk sets consisting of female cohort members alive and free of cancer (except non-melanoma skin cancer) at the time of diagnosis of the index case. Matching criteria were age at enrolment, follow-up time, time of the day of blood collection and study centre. Diet was measured through validated questionnaires. Serum hormone concentrations were measured by enzyme-linked immunosorbent assays. The relationship between serum IGF-I, IGFBP-3, and intake of nutrients and foods was explored by linear regression in models adjusted for energy intake, age, body mass index, smoking, physical activity, centre and laboratory batch.

RESULTS

Serum IGF-I levels were positively related to protein intake (P(trend)<0.001), but not related to energy, fat or carbohydrate intake. Positive relationships were observed with the intake of milk (P(trend)=0.007), calcium (P(trend)<0.001), magnesium (P(trend)=0.003), phosphorus (P(trend)<0.001), potassium (P(trend)=0.002), vitamin B6 (P(trend)=0.03), vitamin B2 (P(trend)=0.001) and inverse relationships with vegetables (P(trend)=0.02) and beta-carotene (P(trend)=0.02). IGFBP-3 was not related with most of the nutrients and foods in this study.

CONCLUSIONS

In this population, circulating IGF-I is modestly related with the intake of protein and minerals, and with milk and cheese, while IGFBP-3 does not appear to be related with diet.

Sequential, randomized trial of a low-fat, high-fiber diet and soy supplementation: effects on circulating IGF-I and its binding proteins in premenopausal women

Despite evidence supporting the involvement of the IGF system in the development of breast and other cancers, the major determinants of interindividual variability in circulatory IGF-I levels are not well understood. Previous research has pointed to important genetic influences as well as dietary effects through marked calorie or protein restriction. We conducted a randomized trial to determine the effects of 2 dietary patterns on serum IGF-1, IGFBP1 and IGFBP3 in free-living premenopausal women: phase 1, an isocaloric low-fat, high-fiber (LFHF) vs. usual diet, and phase 2, a soy supplement either with or without isoflavones (soy+IF vs. soy-IF). Participants completed 12 menstrual cycles on phase 1 and then were randomly assigned to a soy supplement for 3 cycles while maintaining the phase 1 diet. Before and after each phase, 154 women provided serum. We found no difference in the change in IGF-I, BP1 or BP3 in the LFHF group compared to the usual diet group. In phase 2, there were no differences in any IGF protein between the soy+IF and the soy-IF groups or any evidence of interaction between isoflavone exposure and the background diet. However, there was a small but statistically significant decrease (2.3%) in BP3 and an increase in the IGF-I:BP3 molar ratio among all 153 subjects following either soy supplement. These changes were correlated with changes in intake of calcium, total vegetable protein and soy. The results are compatible with previous data suggesting that increases in dietary calcium, protein and soy, in particular, could increase circulating levels of bioavailable IGF-I.

Chromium picolinate may favorably influence the vascular risk associated with smoking by combating cortisol-induced insulin resistance

Smoking promotes insulin resistance and other features - excepting hypertension - of the insulin resistance syndrome; these effects appear to reflect chronic nicotine exposure. The adverse impact of smoking on insulin function may be a prominent mediator of the excess vascular risk associated with smoking. Although the mechanistic basis of nicotine-induced insulin resistance remains to be clarified, increased secretion of ACTH and cortisol seems likely to play an important role in this regard. It is therefore intriguing to note that supplemental chromium picolinate has been reported to have a rapid and substantial favorable impact on glycemic control in patients with corticosteroid-induced diabetes. In dexamethasone-treated rats, high doses of this compound have been shown to markedly improve insulin sensitivity. Thus, if these initial reports are confirmable, ample intakes of bioactive chromium may have the potential to reverse the negative influence of corticosteroids on insulin signaling. Such an effect might have utility not only for smokers, but for others in whom chronic up-regulation of the hypothalamic-pituitary-adrenal axis compromises vascular health. The impact of chromium picolinate on smoking- or nicotine-induced insulin resistance merits study.

Relation of height, body mass, energy intake, and physical activity to risk of renal cell carcinoma: results from the Netherlands Cohort Study

Data from the Netherlands Cohort Study on Diet and Cancer were used to investigate the association between anthropometry, energy intake, and physical activity and risk of renal cell carcinoma (RCC). The Netherlands Cohort Study on Diet and Cancer consists of 120,852 men and women aged 55-69 years who completed a self-administered questionnaire at baseline (1986). A case-cohort approach was used. After 9.3 years of follow-up, 275 microscopically confirmed incident cases were available for analysis. Incidence rate ratios for RCC were estimated using Cox proportional hazards models. Height was associated with RCC risk only in women (per 5-cm increment, rate ratio (RR) = 1.23, 95% confidence interval (CI): 1.03, 1.46). Body mass index (weight (kg)/height (m)(2)) was associated with increased risk of RCC (per 1-kg/m(2 )increment, RR = 1.07, 95% CI: 1.02, 1.12) for men and women, as was gain in body mass index from age 20 years to baseline (per 1-kg/m(2 )increment, RR = 1.06, 95% CI: 1.01, 1.10). Energy intake was not related to RCC risk, while a possible protective effect was observed for physical activity in men. These results suggest that body mass index and gain in body mass index since age 20 are associated with increased risk of RCC.